What is the MARA Appliance?
The MARA appliance is one of many orthodontic devices that is designed to correct overbites (actually called overjet in the dental community). The MARA (short for Mandibular Anterior Repositioning Device) is made by Allessee Orthodontics Laboratory in Sturtevant, Wisconsin. Because is it non-removable by the patient, it fits into the category of “fixed functional appliances.” Although there may be variations in design, the MARA appliance is basically a CAM system that requires a patient to position their lower jaw forward in order to bring their front teeth together. It is called a functional appliance because it requires the patient to function with their jaw in the desired position theoretically encouraging the jaw to “grow” there. Basic MARA design employs a horizontal “arm” in the lower arch that extends sideways from a stainless steel crown on the lower first molar. A crown on the upper first molar has a vertical “elbow” that guides the lower jaw forward into the desired position. When correctly adjusted, the only way the patient can bite down is to slide the lower jaw forward so that the lower arms slip in front of the elbows.
As with any orthodontic tool, the MARA has advantages and disadvantages. Advantages are that it is permanently attached to the teeth and cannot be removed by the patient, it is completely invisible from the outside of the mouth, it can be used before or during the braces phase of treatment, and there is no connection between the upper and lower jaws (so a patient can open his or her jaw as wide as they want). The disadvantages are that it can irritate the cheeks in some patients, it is not always effective in patients with extreme overbites (if they can bite behind the elbows rather than in front of them), and it is not effective in patients with open bites.
As with ALL functional appliances, the MARA reduces overbites primarily by shifting the teeth and not the jaws. In the case of Class II (overbite) correctors like the MARA (also Herbst, Forsus, Twin Block, Bionator, Frankel, etc.), the lower front teeth are tipped forward while the upper teeth are tipped back camouflaging the different jaw sizes. There may also be some effect on the height of the face (opening the bite) which can be desireable in deep bite cases but contraindicated in open bite patients. As much as we wish functional appliances could cause the jaws to grow more than they would on their own, there is no scientific evidence to support that they do. They are effective however in reducing the amount of overbite and are therefore useful in many patients regardless of how the results are achieved.
NOTE: The author, Dr. Greg Jorgensen, is a board-certified orthodontist who is in the private practice of orthodontics in Rio Rancho, New Mexico (a suburb on the Westside of Albuquerque). He was trained at BYU, Washington University in St. Louis, and the University of Iowa in the United States. Dr. Jorgensen’s 25 years of specialty practice and nearly 10,000 finished cases qualify him an expert in two-phase treatment, extraction and non-extraction therapy, functional orthodontics, clear aligners (Invisalign), and multiple bracket systems (including conventional braces, Damon and other self-ligating brackets, Suresmile, and lingual braces). This blog is for informational purposes only and is designed to help consumers understand currently accepted orthodontic concepts. It is not a venue for debating alternative treatment theories. Dr. Jorgensen is licensed to diagnose and treat patients only in the state of New Mexico. He cannot diagnose cases described in comments nor can he select treatment plans for readers. Please understand that because he has over 35,000 readers each month, IT IS IMPOSSIBLE FOR HIM TO RESPOND TO EVERY QUESTION. Please read all of the comments associated with each article as most of the questions he receives each week have been asked and answered previously. The opinions expressed here are protected by copyright laws and can only be used with written permission from the author.